Liquid blending control



June 4, 1963 Filed April 8. 1960 3 Sheets$heet 1 10 COMPUTER COMBINATOR J DIFFERENTIAL SELECTOR 1/ CONE SET/ IllbllllllllllilllllHlllllllllhlllhh 25v METER 4L f C 1 3 5 PUMP PUMP l F l6. 1 LOW HIGH OCTANE OCTANE INVENTOR.., WILLIAM v E. STEEN June 4, 1963 Filed April 8, 1960 FIG. 2

w. E. STEEN 3,092,129

LIQUID BLENDING CONTROL 3 Sheets-Sheet 2 45 INVENTOR.

WILL/AM E. STEEN BY FIG. 4 M *M Attorneys June 4, 1963 w. E. STEEN 3,092,129

LIQUID BLENDING CONTROL Filed April 8. 1960 3 Sheets-Sheet s I E III- I In nun-Inn.-

lmiVI/I/l I-II INVENTOR. WILLIAM E. STEEN Attorneys 3,002,129 Patented June 4, 1963 3,092,129 LIQUID BLENDIN G CONTROL William E. Steen, South Pasadena, Calif., assignor to A. 0. Smith Corporation, Milwaukee, Wis., a corporation of New York Filed Apr. 8, 1960, Ser. No. 20,852 2 Claims. (Cl. 137-400) This invention relates to a liquid blending control and is particularly directed to controlling the delivery of two gasolines of diiferent octane rating to a single discharge point to establish a gasoline having an intermediate octane rating determined by the ratio of the two gasolines.

Until recently gasolines for motor car consumption have been sold in two grades conventionally denoted as regular or low-test and high-test. The regular or low-test gasoline is somewhat less expensive. The hightest gasoline is, however, necessary for eflicient and smooth operation of high-compression engines. As set forth in United States Patent 2,880,908 to E. R. Young, automobiles presently in use have many different octane requirements and consequently a demand has arisen for a greater number of octane ratings in gasoline. To provide completely separate dispensing systems for each of the grades or octane ratings would result in a prohibitive investment. Blending systems have been suggested which variously and selectively combine the two conventional grades of gasoline and thereby provide intermediate grades of gasolines having predetermined octane ratings.

Generally, prior art blending structures employ completely separate and individual controls and gear connections to couple individual pumps and individual control valves for the several gasolines to be mixed. The control valves are coupled to the associated meters and positioned in opposite directions to control the final blend of the gasolines by simultaneously increasing the fiow of one rating and decreasing the flow of the other. This necessarily requires the use of separate gear boxes which must be individually adjusted to establish a sufficient selection of intermediate grades of gasolines.

In accordance with the present invention, the two storage tanks for the two gasolines are connected through a single multiple port control valve to the discharge nozzle or dispenser. The valve is driven through a differential gear system having each of the meters as an input drive. A gear ratio change mechanism is interposed in the drive between one of the meters and the differential gear system. The gear ratio changer allows adjustment of the output speed of the corresponding meter for a predetermined input. Consequently the input to the differential can be varied for any predetermined flow through the corresponding meter. With the inputs from the two meters to the differential gear system rotating at the same speed, the output shaft from the differential is zero and the shaft is stationary holding the multiple port valve in a predetermined position. If however either of the inputs to the differential is at a different speed, the output shaft is driven in accordance with the difference in the angular velocity in a direction determined by which of the two speeds is the greater. The multiple port valve is thus actuated to change the ratio of the gases being delivered. The change in the ratio of the gases is such that the meters inversely change the input to the differential in a direction tending to establish equal input speeds to the differential. When the correct ratio is being delivered, the difierential output is Zero and the valve positioning shaft is stationary.

By suitable selection of the gear ratio changer, the drive for the multiple port valve correctly positions and maintains the position to establish a predetermined blend of the two gasolines and thereby establish an intermediate octane rating.

The use of a single-point-control multiple port valve to regulate the dispensing of the two gases is exceedingly positive and accurately meters the discharge of the fluids. Where two separate valves are employed and controlled from a single control point, inaccuracies may be inserted into the control.

The gear ratio changer in accordance with the present invention employs in series relationship a main cone gear and a secondary cone gear adapted to establish a series of octane rating ranges. The output of the main cone gear is connected to the secondary cone gear to provide fine adjustment within each of the ranges established by the main cone gear. The combination of the wide range control with the fine adjustment control Within each of the wide ranges establishes an exceedingly large number of different octane ratings. The present invention is preferably intended to be sealed within a suitable housing such that it is not readily changed without removing releasably mounted covers and the like.

The secondary cone gear establishes an exceedingl positive and accurate adjustment to regulate the flow from the two meters with a single recording register and counter.

The drawings furnished herewith illustrate the best mode presently contemplated for carrying out the inven tion.

In the drawings:

FIG. 1 is a diagrammatic illustration of a liquid pumping assembly constructed in accordance with the present invention;

FIG. 2 is a side sectional view of a valve positioning control in accordance with the present invention as shown in FIG. 1;

FIG. 3 is a bottom view of FIG. 2;

' FIG. 4 is an end view of a portionof the gear change mechanism viewed from the right in FIGS. 2 and 3;

FIG. 5 is a simplified gear layout illustrating a gear train for one setting of the valve positioning control;

FIG. 6 is an end view of a fine adjustment control con stituting a part of the gear change mechanism shown in FIGS. 2 and 3;

FIG. 7 is a view taken on line 77 of FIG. 6;

FIG. 8 is an enlarged view of a ratio control valve diagrammatically shown in FIG. 2; and

FIG. 9 is an end view of the FIG. 8 taken on line 8 8, with parts broken away to show the inner details of construction.

Referring to the drawings, and particularly to FIG. 1, a gasoline dispensing system is diagrammatically illustrated including a high octane gasoline storage tank 1 and a low octane gasoline storage tank 2. Suitable pumps 3 are connected to the output side of the storage tanks 1 and 2 and are adapted to withdraw the fluid from the corresponding storage tank and transfer the gasoline to a ratio control valve 4 andthen to a discharge nozzle 5 for distribution to a consumer. A high octane meter 6 is connected in the line between the corresponding pump 3 and the ratio control valve 4. Similarly a low octane meter 7 is connected between the corresponding pump 3 and the ratiov control valve 4. Meters 6 and 7 are driven by the flow of gas through the meters and establish a mechanical output proportional to the volume of the gasoline pumped through the meter.

The mechanical output of each of the meters 6 and 7 is connected through similar gear connections 8 to a differential combinator 9 which is adapted to sense the volume flowing through each of the meters and to combine them to establish an output proportional to the total is also connected as an input to a differential gear unit 11 having a single output connected to a control valve positioning shaft 12. The ratio control valve 4 is connected to the shaft 12 and positioned in accordance with the ratio of the inputs to the differential gear unit 11.

As appears more fully hereinafter, when equal rota tional inputs are applied to the differential gear unit 11 from the meters 6 and 7, the positioning shaft 12 is stationary. However, if either input increases or decreases in speed relative to the other, the differential gear unit 11 drives the shaft 12 and the connected control valve 4 to vary the rate of discharge of the two gases in a direction to re-establish equal inputs to the differential gear unit 11. A gear ratio selector 13 is connected in series between the high octane meter 6 and the differential gear unit 11 to allow varying the drive ratio between the output of meter 6 and the corresponding input to differential gear unit 11.

Assume an intermediate octane rating is desired consisting of three parts of high octane gasoline to each part of low octane gasoline. Meter 6 must operate at three times the rate of the meter 7 in order that the three-toone ratio is established. The gear ratio selector 13 is arranged to establish an input to the differential gear unit 11 which is one-third the output of the meter 6. The inputs to the differential gear unit 11 are therefore not equal until the meter 6 is driven three times as fast as meter 7. The gear unit 11 drives shaft 12 to position the multi-port valve 4 necessary to establish the three-to-one ratio drive. When this valve position is established, the inputs to the differential gear unit 11 are equal and the rotation of shaft 12 stops.

If any other ratio is desired, the gear ratio selector 13 must be re-established in accordance with the ratio of the two gasolines to be provided at the nozzle 5.

Referring particularly to FIGS. 2 and 3, the gear ratio selector 13 is shown connected to the differential gear unit 11 and carried by a common supporting frame structure 14. The supporting frame structure 14 also supports the combinator 9 and is adapted to be mounted within a suitable pump casing 15.

A low octane meter shaft 16, shown in the left portion of FIGS. 2 and 3, establishes a rotational input in accordance with the rate of liquid flow through the low octane meter 7. Bevel gears 17 connect the shaft 16 to a transmission shaft 18 which projects axially from the gears 17 and is journaled in suitable bearing and partition walls 19. A gear train 20 connects one end of the transmission shaft 18 to a planetary gear assembly 21 constituting the drive gears of combinator 9. The transmission shaft 18 thus constitutes an input to the planetary gear assembly 21 to drive the combinator 9 in accordance with the speed of the shaft 16 from meter 7. An output shaft 22 is connected by a set of bevel gears 23 to the output of gear assembly 21 and is coupled to the computer It) to record the volume of the low octane gas pumped through the meter 7.

A series of gears 24 connects the opposite end of the transmission shaft 18 as an input to a valve control planetary gear assembly 25 which constitutes the drive portion of differential gear unit 11 illustrated in FIG. 1.

A meter shaft 26 of the high octane meter 6 is connected to a transmission shaft 27 shown in the upper central portion of FIGS. 2 and 3, by suitable bevel gears 28. A gear train 29 connects the transmission shaft 27 to the gear assembly 21 to drive the gear assembly simultaneously with the drive from the transmission shaft 18 which is driven by meter 7.

The illustrated planetary gear assembly 21 is a standard construction to establish a rotating output in accordance with the sum of the two rotating inputs established by meters 6 and 7. Two planetary gears or pinions 30 are interconnected in equicircumferentially spaced relation by a yoke 31. A sun gear 32 is secured to an output shaft 33 in constant mesh with the pinions 30. The output shaft 33 rotatably supports the yoke 31 which is connected by the gear train 20 to the transmission shaft 18. A gear 34 is rotatably supported upon shaft 33 in mesh with pinions 30 and connected by gear train 29 to the transmission shaft 27 which is driven by meter 7. Yoke 31 and gear 34 are simultaneously rotated and the sun gear 32 rotates in accordance with the sum of the rotational speed of the yoke 31 and gear 34. Consequently, the output shaft 33 rotates at an angular velocity equal to the sum of the input velocities from the meter shafts 16 and 26. Bevel gears 23 connect the output shaft 33 to the drive shaft 22 connected with computer 10 to record the total volume of gas delivered by meters 6 and 7.

Referring particularly to FIGS. 2-5, the transmission shaft 27 is connected through the gear ratio selector 13 to drive an idler shaft 35 which is coupled by a gear train 36 to drive the gear assembly 25. Gear assembly 25 is generally similar to gear assembly 21 and includes a sun gear 37 connected to an output shaft 38. Two planetary pinions 39 are connected in angularly spaced relation to a yoke 46 which is driven by the gear train 24. A gear 41 is rotatably mounted upon output shaft 38 and driven by gear train 36. The gear 41 and the yoke 41) are driven in opposite direction to drive the sun gear 37 as the difference in the speeds in gear 41 and yoke 46. The output shaft 38 is therefore driven as the difference in the outputs of the meters 6 and 7 which is applied to planetary gear assembly 25.

The drive from shaft 16 of meter 7 is held at a constant ratio to drive the planetary assembly 25 in accordance with the flow through meter 7. The drive from shaft 26 of meter 6 is adjusted to drive the planetary assembly 25 at a preselected ratio or percentage of the flow through meter 6. The gear 41 is thus driven at a reduced speed and the flow through meter 6 must be increased if the gear 41 is to rotate at the same speed as the yoke 40 which is driven by meter 7. The gear ratio selector :13 determines the drive ratio and the required relative speeds of meters 6 and 7 to establish similar inputs to planetary assembly 25.

Referring particularly to FIGS. 2-4, the gear ratio selector 13 is mounted within a suitable support 42 which is secured to mounting support 14. The selector 13 comprises a five-step cone gear unit 43 establishing a five drive ratio and a calibrater gear unit 44 connected in series with unit 43 to further vary each of the five drive ratios by relative small similar increments.

The five-step cone gear unit 43 includes a cone gear 45 consisting of five different diameter gears keyed to a common shaft 46. A sliding gear carrier 47 is pivotally mounted to a coupling shaft 43extending parallel to the axis of cone gear 45. The gear carrier 47 is adapted to be positioned on shaft 48 in alignment with any one of the gears forming the cone gear 45. The sliding gear carrier 47 consists of a pair of gear plates which are secured together in axially spaced relation by a pair of bolts 49 with spacers 50 establishing the spacing of the plates. An idler gear 511 is rotatably journaled between the plates of carrier 47 in mesh with the aligned gear of the cone gear 45. An input gear '52 is journaled on the coupling shaft 48 by a hub 53 which is mounted on shaft 48 between the plates forming carrier 47. Gear 52 constantly meshes with the idler gear 51 as the carrier 47 pivots about shaft 48. Gear 52 is driven by a gear 54 on a shaft 55 which projects parallel to transmission shaft 27 and overlaps with a portion of shaft 27. A gear 56 couples transmission shaft 27 to the shaft 55 to drive the shaft 55 in a direct relationship to the speed of transmission shaft 27. Rotation of the shaft 27 from meter 6 is thus transmitted directly to the gear cone unit 43.

The free end of gear carrier 47 is provided with slots 56 which accommodate a locking shaft 57 to releasably lock the carrier 47 in alignment with a preselected gear of gear cone 45. Shaft57is threaded and rotatably supported parallel to the shaft 46 of cone gear 45. A tubular spacer 58 is disposed between the plates of carrier 47 and positioning nuts 59 and 60 are threaded on shaft 57 on opposite sides of the carrier. The carrier 47 is positioned by simultaneous or sequential movement of the positioning nuts 59 and 60' in the direction of the desired axial positioning of the carrier 47. As carrier 47 moves axially upon the shaft 57, the input gear 52 and idler gear 51 are axially positioned with respect to the cone gear 45. Slots '56 permit the carrier 47 to pivot and position gear 51 into engagement with a preselected one of the gears of cone gear 45 after which nuts 59' and 60 are drawn up to clamp the carrier in place.

Referring particularly to FIG. 5, the transmission system bet-ween the shaft and the cone gear 45 is more clearly diagrammatically illustrated.

The common shaft 46 of cone gear 45 is thereby rotated in accordance with the ratio between the gear 51 and the aligned cone gear 45. The five-step cone gear 45 establishes five different drive ratios.

An output gear 61 is connected to the common shaft 46 and meshes with an input gear 62 carried by an input shaft 63 of the calibrater gear unit 44.

Referring particularly to FIGS. 6 and 7, the calibrater gear unit 44 includes the input shaft 63 journaled within a calibrater gear unit housing 64. A pair of series connected planetary gear units 65 and 66 connect the input shaft 63 to the output shaft 35 which is coupled to planetary gear assembly 25 by the gear train as shown in FIG. 3.

Each of the illustrated planetary units is similar to those previously described and no further detailed description is provided.

The gear unit 65 is driven directly by input shaft 63 and drives the gear unit 66. A portion of the drive from shaft 63 is diverted through a gear train 67 to drive an eleven-step cone gear 68 and establish a pair of adjustable drives which are fed back into the planetary gear units 65 and 66.

A pair of sliding gears 69' and 7 0 are slidably keyed to output shafts 71 and 72 on opposite sides of the cone gear 68. The axes of shafts 71 and 72 are parallel to the surface enveloping the cone gear 68 such that as the gears 69 and 70 are positioned on the shafts different gears of cone gear 63 are engaged. Gears 69 and 70 are similarly positioned as follows.

A control bar 73 is secured to each of the sliding gears 69 and 76. Control bar 73 extends through an opening in a front plate 74 of the housing 64. Control bar 73 includes a series of similar notches 75 which are adapted to engage the adjacent edge of the front plate 74 and lock the bar in position. The actuating bar 73 includes eleven notches spaced in accordance with the gears of cone gear 68. The sliding gears 69 and 70 mesh with one of the eleven gears constituting the cone gear 68. The output shafts 71 and 72 consequently are driven in accordance with the ratio of the engaged gear of the cone gear 68 with respect to the corresponding sliding gears 69 and 70.

Similar gear trains 76 and 77 couple the respective output shafts 71 and 72 as inputs to the planetary units 65 and 66. Gear train 76 couples the output shaft 71 to the planetary unit 65 which is also driven directly by the input shaft 63.

The planetary unit 65 thus establishes an output which is equal to the input established by shaft 63 less the input established by the positioning of sliding gear 69. The output of planetary unit 65 is transmitted through a transmission hub 78 which carries the output gear of planetary unit 65 and one input gear of planetary unit 66.

The rotational speed of the second planetary unit 66 is determined by the input speed of the hub 78 less the speed of output shaft 72 which is connected to the sliding gear 70. The second planetary unit 66 includes a tubular coupling member which is connected to the shaft 35 leading to gear assembly 25 through the gear train 36, as shown in FIG. 3.

The eleven-step cone gear 68 in cooperation with a pair of sliding gears 69 and 70 establishes 121 different adjustments varying by 1 of one percent in the ratio between the speed of the input shaft 63 and the idler shaft 35. Consequently, within each of the wide ranges established by the cone gear unit 43, 121 further ratios are provided. By suitable adjustment of the carrier 47 of gear unit 43 and of the notched bars 73 of the calibrater gear unit 44, the calibrater 13 provides dilferent ratios between the input from the high octane meter 7 and the output to the differential gear unit 11. Consequently, the ratio of the liquid from storage tank 2 with respect to storage tank 1 may be correspondingly varied and a similar number of octane ratings provided.

The gear train 36 in FIG. 3 is selected to drive the gear assembly 25 in an opposite direction with respect to drive of the gear train 21. The gear train 36 is driven by the high octane meter 6 and gear train 21 is driven by the low octane meter 7. Consequently, the output shaft 38 of gear assembly 25 is driven as the difference of the above inputs to gear assembly 25. If the input speeds to the gear assembly 25 are equal, the output shaft 38 is stationary.

' Referring particularly to FIGS. 2 and 3, a worm 79 is secured to the shaft 38 and maintained in mesh with a worm wheel 80 which is secured to the positioning shaft 12 for the control valve 4. The shaft 12 is slidably journaled within the supporting frame 14 and con nected to selectively position the control valve 4 in the following manner.

Referring particularly to FIGS. 8 and 9, the details of a multi-port valve 4 is illustrated. Generally the valve includes a valve housing 81 having a high octane inlet port 82 connected to the output of a high octane meter 6 and a low octane inlet port 83 connected to the output of the low octane meter 7. A blended fuel discharge port 84 is connected to the nozzle 5. A pair of side-byside annular chambers 85 and 86 are formed in the wall of the valve housing 81 and connect the discharge port 84 to the high octane inlet port 82 and the low octane inlet port 83, respectively. A sleeve-type drum 87 'is slidably journaled within the housing 81 for axial move ment relative the side-by-side annular chambers 85 and 86. A series of circumferential slots 88 and 89 are axially spaced in the sleeve drum 87 in accordance with the openings to the annular chambers 85 and 86. The drum 87 is positioned to inversely open and close the opening 'between the contiguous chambers 85 and 86 with respect to the discharge port 84 and thus to inversely vary the amount of gasoline flow from the corresponding inlet ports 82 and 83. The positioning of the sleeve drum 87 to increase the flow of the high octane gasoline through inlet port 82 establishes a corresponding 'decrease in the flow of low octane gasoline through the inlet port 83. Consequently, the mixture is very accurately and precisely controlled without any possible inaccuracy arising because of a non-similar adjustment in the two control openings.

The outer end of sleeve drum 87 is closed by a wall 90 having a threaded recess to receive a correspondingly threaded end of the positioning shaft 12 within valve housing 81. The shaft 12 includes a second threaded portion 91 which threads into a threaded opening in a removable end wall 92 of housing 81. End wall 92 is bolted or otherwise secured to housing 81 such that rotation of the shaft 12 causes the shaft to move axially through the housing 81. The axial positioning of the shaft 12 in turn correspondingly positions the sleeve drum 87 within the housing to simultaneously inversely adjust the registration of the slots 88 and 89 with respective annular chambers 85 and 86.

The operation of the illustrated embodiment of the invention is generally summarized as follows.

The calibrater 13 is preset to establish any preselected mixture of gasolines from storage tanks 1 and 2 within.

the 600 permissible mixtures which the series connected 7 which in turn actuate the differential gear unit 11 to.

rapidly position the multi-port valve 4 for the correct mixture. Once preset, the apparatus is intended to supply fuel of that octane rating for substantial number of successive deliveries. Consequently, the amount of fuel withdrawn to initially set valve 4 is inconsequential.

As fuel is initially drawn from storage tanks 1 and 2,1 the meters 6 and 7 rotate at the same speed. The gear ratio selector 13 however reduces the output speed transmitted from meter 6 to the differential 11 by the desired ratio of fuel to be delivered.

The output shaft 38 of the differential rotates the shaft 12 and repositions the drum 87 of valve 4 to increase the high octane opening between port 82 and discharge port 84 and to simultaneously decrease the low octane opening between port 83 and discharge port 84.

The output from storage tank 1 increases and the output of meter 6 increases accordingly. The output of the gear ratio selector 13 increases proportionately and thus reduces the difference in the inputs to the differentialgear unit 11. The difference is reduced to zero when the correct ratio of fuel is being delivered and shaft 12 is subsequently held stationary.

Subsequently, it either of the fuel deliveries varies to change the ratio, the inputs to the differential-gear unit 11 vary accordingly. The gear unit 11 is thus actuated to immediately reposition the single, multi-port valve 4 and reestablish the desired mixture.

When the present octane rating is to be replaced with another, the pump housing is opened and the selector 13. adjusted accordingly. The exceedingly large number of ratings possible with the illustrated embodiment of the invention permit a single unit to be used in many different geographical areas which will require the same vehicle to operate on slightly different octane ratings for most efficient operation.

A single, multi-port valve permits accurate and positive positioning of the valve openings between the nozzle and the two storage units for the fuels being blended.

The single selector gear assembly prevents errors which might arise in prior art structure which employ individually adjusted separate valve devices in eachof the fuel lines. The series cone gear assemblies provide a great number of positive and accurate adjustments of the mixture and resultant octane ratings of the fuel.

Various modes of carrying out the invention are contemplated as within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

I claim:

1. In a liquid blender for maintaining proportional flow of two liquids to a single discharge, a multi-port valve having a pair of inlets connected to the two liquids. and an outlet to deliver the mixture of the two liquids and having a single movable valve member to inversely adjust the connection of the outlet to the pair of inlets, a differential gear unit having a pair of opposing inputs and an output connected to position said movable valve member as the difference in the inputs, a meter responsive to the flow of one of said liquids and connected to one of the inputs of said differential gear unit to drive the same, and a second meter responsive to the flow of the other of said liquids and connected to the other input of said differential gear unit to drive the same, one of said meter connections comprising an adjustable drive connected to be driven by the corresponding meter, 21 pair of series connected planetary transmissions connecting said adjustable drive to said differential gear unit, and a cone gear drive having an input connected to the adjustable drive and having a pair of separately adjustable outputs connected one each to each of said planetary transmissions to establish a plurality of presettable drive ratios between the corresponding meter and the differential gear unit.

2. In a liquid blender for maintaining proportional flow of two liquids to a single discharge, valve means to adjust the ratio of flow of the two liquids to the single discharge, a differential gear unit having a pair of opposing inputs and an output connected to position said valve means as the difference in the inputs to adjust the ratio of flow, meter means responsive to the flow of one of said liquids and connected to one of said inputs of said differential gear unit to drive said differential gear unit, and second meter means responsive to the flow of the other of said liquids and connected to the other input of said differential gear unit to drive the same, one of said meter connections comprising a multi-step cone gear connected to be driven by the corresponding meter, a pair of series connected planetary transmissions connecting said multistep cone gear drive to said differential gear unit, and a second cone gear drive having an input connected to the output of said first named cone gear drive and having a pair of separately adjustable outputs connected one each to each of said planetary transmissions to modify the output thereof and thereby the corresponding input to said dilferential gear unit for any selected drive speed of said multi-step cone gear.

References Cited in the file of this patent UNITED STATES PATENTS 1,926,333 Fulcher Sept. 12, 1933 2,195,005 Grosvenor et al Mar. 26, 1940 2,530,310 McFarland Nov. 14, 1950 2,624,360 Goddard Jan. 6, 1953 2,742,923 Show Apr. 24, 1956 2,881,639 Holtan Apr. 14, 1959 2,977,970 Young Apr. 4, 1961 FOREIGN PATENTS 1,156,430 France May 16, 1958 

1. IN A LIQUID BLENDER FOR MAINTAINING PROPORTIONAL FLOW OF TWO LIQUIDS TO A SINGLE DISCHARGE, A MULTI-PORT VALVE HAVING A PAIR OF INLETS CONNECTED TO THE TWO LIQUIDS AND AN OUTLET TO DELIVER THE MIXTURE OF THE TWO LIQUIDS AND HAVING A SINGLE MOVABLE VALVE MEMBER TO INVERSELY ADJUST THE CONNECTION OF THE OUTLET TO THE PAIR OF INLETS, A DIFFERENTIAL GEAR UNIT HAVING A PAIR OF OPPOSING INPUTS AND AN OUTPUT CONNECTED TO POSITION SAID MOVABLE VALVE MEMBER AS THE DIFFERENCE IN THE INPUTS, A METER RESPONSIVE TO THE FLOW OF ONE OF SAID LIQUIDS AND CONNECTED TO ONE OF THE INPUTS OF SAID DIFFERENTIAL GEAR UNIT TO DRIVE THE SAME, AND A SECOND METER RESPONSIVE TO THE FLOW OF THE OTHER OF SAID LIQUIDS AND CONNECTED TO THE OTHER INPUT OF SAID DIFFERENTIAL GEAR UNIT TO DRIVE THE SAME, ONE OF SAID METER CONNECTIONS COMPRISING AN ADJUSTABLE DRIVE CONNECTED TO BE DRIVEN BY THE CORRESPONDING METER, A PAIR OF SERIES CONNECTED PLANETARY TRANSMISSIONS CONNECTING SAID ADJUSTABLE DRIVE TO SAID DIFFERENTIAL GEAR UNIT, AND A CONE GEAR DRIVE AND HAVING AN INPUT CONNECTED TO THE ADJUSTABLE DRIVE AND HAVING A PAIR OF SEPERATELY ADJUSTABLE OUTPUTS CONNECTED ONE EACH TO EACH OF SAID PLANETARY TRANSMISSIONS TO ESTABLISH A PLURALITY OF PRESETTABLE DRIVE RATIOS BETWEEN THE CORRESPONDING METER AND THE DIFFERENTIAL GEAR UNIT. 